Thanks to everyone for suggestions on how to work around the problem of not being able to send to lists as postmaster. I think we will be able to manage new list requests with a ListManager account by having the requests sent to an IMAP account to which all of the postmaster will have access. One other question, though. The documentation refers to the forbidden addresses as "MAILER, POSTMASTER, ROOT, UUCP, et al." What are the others included in et al? We have a number of automated e-mail processes, some of which come from root on Unix machines. We also have some PCs that send mail as "administrator@whatever". Is administrator another forbidden address?